The Ontario Ministry of Agriculture, Food & Rural Affairs offers valuable information about pesticides, and precautions to protect the environment where pesticides are used. Of special interest to beekeepers is the section called Prevent Bee Poisoning, which reminds the agricultural community that honeybees are vital pollinators and can be greatly harmed by careless pesticide application.
Recommendations to pesticide users include telling beekeepers of the intent to spray, so they have a chance to move their hives, and spraying on those days when weather conditions will minimize wind-drift as well as the chance of bees being out at forage.
A chart divides common agricultural pesticides into two groups — those that are very toxic to bees and should not be sprayed on flowering crops or weeds, and those that should be applied only in early morning or late evening.
The list of pesticides that are very toxic to bees includes:
- Basudin, Diazinon (diazinon)
- Cygon, Lagon (dimethoate)
- Furadan (carbofuran)
- Guthion, Sniper (azinphos-methyl)
- Imidan (phosmet)
- Lannate (methomyl)
- Lorsban, Pyrifos, Pyrinex (chlorpyrifos)
- Malathion (malathion)
- Ripcord, Cymbush (cypermethrin)
- Sevin (carbaryl)
The following pesticides should be applied only in early morning or late evening, those times of day when bees are less likely to be foraging:
- Decis (deltamethrin)
- Dylox (trichlorfon)
- Endosulfan, Thiodan, Thionex (endosulfan)
“Unusually low temperatures at time of application may cause insectides to remain toxic up to 20 times longer than during warm weather,” the OMFRA notes. “High temperatures in the early morning or late evening may extend active foraging by bees.”
English link:
http://www.omafra.gov.on.ca/english/crops/resource/1protect2.htm#prevent
French link:
http://www.omafra.gov.on.ca/french/crops/pub75/3protec2.htm#prevent
Written by beekeepers
Topics: How to Keep Bees